From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933725AbaLKEJ0 (ORCPT ); Wed, 10 Dec 2014 23:09:26 -0500 Received: from smtprelay0217.hostedemail.com ([216.40.44.217]:55163 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933529AbaLKEJZ (ORCPT ); Wed, 10 Dec 2014 23:09:25 -0500 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 50,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::,RULES_HIT:41:355:379:541:599:800:960:967:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2525:2553:2560:2563:2682:2685:2859:2895:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3622:3653:3865:3867:3868:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:7875:8599:8660:8957:9025:9040:10004:10400:10450:10455:10848:10967:11026:11232:11473:11658:11914:12043:12050:12295:12438:12517:12519:12555:12740:12783:13069:13148:13230:13311:13357:14096:14097:19904:19999:21060:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: salt84_8c3851d36c249 X-Filterd-Recvd-Size: 2725 Date: Wed, 10 Dec 2014 23:09:13 -0500 From: Steven Rostedt To: Fengguang Wu Cc: LKP , linux-kernel@vger.kernel.org Subject: Re: [ftrace/fgraph/x86] BUG: unable to handle kernel paging request at 3d00c17d Message-ID: <20141210230913.0bcbb124@gandalf.local.home> In-Reply-To: <20141210231732.GA24163@wfg-t540p.sh.intel.com> References: <20141210231732.GA24163@wfg-t540p.sh.intel.com> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 10 Dec 2014 15:17:32 -0800 Fengguang Wu wrote: > Hi Steven, > > 0day kernel testing robot got the below dmesg and the first bad commit is > > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > commit 6a06bdbf7f9c669743f58084991ba280f2925586 > Author: Steven Rostedt (Red Hat) > AuthorDate: Mon Nov 24 21:00:34 2014 -0500 > Commit: Steven Rostedt > CommitDate: Mon Dec 1 14:08:58 2014 -0500 > > ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter > > The function graph helper function prepare_ftrace_return() which does the work > to hijack the parent pointer has that parent pointer as its first parameter. > Instead, if we make it the second parameter and have ip as the first parameter > (self_addr), then it can use the %rdi from save_mcount_regs that loads it > already. > > Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos > > Reviewed-by: Thomas Gleixner > Signed-off-by: Steven Rostedt Crap! Yeah, I was wondering how this could be the bug, but then I realized this was i386 not x86_64 and I never updated the i386 call to prepare_ftrace_return(). Does this patch fix it? -- Steve diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index b553ed89e5f5..df3e608d409b 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1192,10 +1192,10 @@ ENTRY(ftrace_graph_caller) pushl %eax pushl %ecx pushl %edx - movl 0xc(%esp), %edx - lea 0x4(%ebp), %eax + movl 0xc(%esp), %eax + lea 0x4(%ebp), %edx movl (%ebp), %ecx - subl $MCOUNT_INSN_SIZE, %edx + subl $MCOUNT_INSN_SIZE, %eax call prepare_ftrace_return popl %edx popl %ecx